title: Recovery of stored aerobic granular sludge and its contaminants removal efficiency under different operation conditions.
abstract: The quick recovery process of contaminants removal of aerobic granular sludge (AGS) is complex, and the influencing factors are still not clear. The effects of dissolved oxygen (DO, air intensive aeration rate), organic loading rate (OLR), and C/N on contaminants removal characteristics of AGS and subsequently long-term operation of AGS bioreactor were investigated in this study. DO had a major impact on the recovery of AGS. The granules reactivated at air intensive aeration rate of 100 L/h achieved better settling property and contaminants removal efficiency. Moreover, protein content in extracellular polymeric substance (EPS) was almost unchanged, which demonstrated that an aeration rate of 100 L/h was more suitable for maintaining the biomass and the structure of AGS. Higher OLR caused polysaccharides content increase in EPS, and unstable C/N resulted in the overgrowth of filamentous bacteria, which presented worse NH4 (+)-N and PO4 (3-)-P removal. Correspondingly, quick recovery of contaminants removal was accomplished in 12 days at the optimized operation conditions of aeration rate 100 L/h, OLR 4 g/L·d, and C/N 100 : 10, with COD, NH4 (+)-N, and PO4 (3-)-P removal efficiencies of 87.2%, 86.9%, and 86.5%, respectively. The renovation of AGS could be successfully utilized as the seed sludge for the rapid start-up of AGS bioreactor.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zhao
authors.forename: Shuo
authors.initials: S
authors.lastname: Wang
authors.forename: Wenxin
authors.initials: W
authors.lastname: Shi
authors.forename: Ji
authors.initials: J
authors.lastname: Li
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D019149:Bioreactors; D010100:Oxygen / Q000737:chemistry / Q000494:pharmacology*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology; D012722:Sewage / Q000382:microbiology*
chemical_list: D011108:Polymers; D012722:Sewage; D010100:Oxygen